1. Field of the Invention
This invention relates to a normal/reverse mode changing mechanism for a newly developed tape transport apparatus, that is, such a mode changing mechanism as to make a tape, which is sandwiched between and driven by a capstan and pinch roller, selectively run in either a first tape transport direction or a second tape transport direction that is in reverse to the first tape transport direction.
Some improvements will be carried out as to a regulating member for regulating the tape transport direction. The regulating member comprises a movable member for transferring the pinch roller and a driving gear that is selectively engaged to one of two reel bases to drive the selected base; and control means for controlling the motion of the movable member which is moved between a first position where a first tape transport mode is obtained and a second position where a second tape transport mode is obtained.
To make one of the two tape transport modes selectively obtainable, a mode changing mechanism of the tape transport apparatus, which merely comprises one movable member, cam means and an electromagnet, will be proposed.
2. Description of the Prior Art
In general, a tape transport apparatus, such as a tape recorder, comprises a pair of reel bases on which a pair of tape reels are mounted, respectively; a transferal gear driven by a motor and capable of selectively engaging one of the pair of reel bases; a capstan driven by the motor; and a pinch roller, and when recording or reproducing is performed, a magnetic tape is firmly sandwiched between the rotated capstan and the pinch roller so as to be run at a constant speed. Simultaneously, one of the pair of reel bases is engaged by the transferable gear, and takes up the magnetic tape which is fed from between the capstan and the pinch roller. Next, when the apparatus is in the fast forward or the rewind mode, one of the pair of reel bases is rotated at a high speed in a direction for taking up the magnetic tape under such a state as to have the pinch roller separated from the capstan.
In various kinds of tape recorders, there is a tape recorder, which is capable of recording and reproducing both at a time when the magnetic tape runs in its normal direction, and at a time when the magnetic tape runs in its reverse direction. This tape recorder has generally two capstans and two pinch rollers corresponding to the respective capstans and the two combinations of a capstan and a pinch roller being disposed on opposite sides of a magnetic head used for recording or reproducing.
Thus, when recording or reproducing (hereinafter described as normal play) is performed under such a state as to run the magnetic tape in the normal direction, one of the pinch rollers is pressed against the corresponding capstan, and when recording or reproducing (hereinafter described as reverse play) is performed under such a state as to run the magnetic tape in the reverse direction, the other of the pinch roller is pressed against the corresponding other capstan. Therefore, in such a tape transport apparatus, it becomes necessary to provide a direction mode changing mechanism which is capable of optionally selecting one of the normal play mode and the reverse play mode.
Up to the present, there are various kinds of direction mode changing mechanisms, but in conventional direction mode changing mechanisms, either the means for transferring the transferable gear and means for selectively transferring one of the pinch rollers are different from each other, a motor for driving the transferable gear and pinch rollers differs from the one used for tape transport, or a plurality of electromagnets are used to select optionally one of the normal play mode and the reverse play mode. Thus, the number of parts are apt to increase, and the cost of production rises.